Use 'sb' name for local 'struct stat' buffers

Deprecate the use of 'st' and other names. The 'sb' name is often seen
in example codes in Linux man pages. (The 'statbuf' name is sometimes
also used but I choose 'sb' name because it's shorter.)

No code changes.

Compat.c

@@ -50,11 +50,11 @@ int Compat_faccessat(int dirfd,
    }
 
    // Fallback to stat(2)/lstat(2) depending on flags
-   struct stat statinfo;
+   struct stat sb;
    if (flags) {
-      ret = lstat(pathname, &statinfo);
+      ret = lstat(pathname, &sb);
    } else {
-      ret = stat(pathname, &statinfo);
+      ret = stat(pathname, &sb);
    }
 
    return ret;

OpenFilesScreen.c

@@ -238,10 +238,10 @@ static OpenFiles_ProcessData* OpenFilesScreen_getProcessData(pid_t pid) {
       item = &fdata->data;
       const char* filename = getDataForType(item, 'n');
 
-      struct stat st;
-      if (stat(filename, &st) == 0) {
+      struct stat sb;
+      if (stat(filename, &sb) == 0) {
          char fileSizeBuf[21]; /* 20 (long long) + 1 (NULL) */
-         xSnprintf(fileSizeBuf, sizeof(fileSizeBuf), "%"PRIu64, (uint64_t)st.st_size); /* st.st_size is long long on macOS, long on linux */
+         xSnprintf(fileSizeBuf, sizeof(fileSizeBuf), "%"PRIu64, (uint64_t)sb.st_size); /* sb.st_size is long long on macOS, long on linux */
          free_and_xStrdup(&item->data[fileSizeIndex], fileSizeBuf);
       }
    }

linux/LinuxProcessTable.c

@@ -490,18 +490,18 @@ static bool LinuxProcessTable_updateUser(const Machine* host, Process* process,
       return true;
    }
 
-   struct stat sstat;
+   struct stat sb;
 #ifdef HAVE_OPENAT
-   int statok = fstat(procFd, &sstat);
+   int statok = fstat(procFd, &sb);
 #else
-   int statok = stat(procFd, &sstat);
+   int statok = stat(procFd, &sb);
 #endif
    if (statok == -1)
       return false;
 
-   if (process->st_uid != sstat.st_uid) {
-      process->st_uid = sstat.st_uid;
-      process->user = UsersTable_getRef(host->usersTable, sstat.st_uid);
+   if (process->st_uid != sb.st_uid) {
+      process->st_uid = sb.st_uid;
+      process->user = UsersTable_getRef(host->usersTable, sb.st_uid);
    }
 
    return true;
@@ -1349,19 +1349,19 @@ static char* LinuxProcessTable_updateTtyDevice(TtyDriver* ttyDrivers, unsigned l
          continue;
       }
       unsigned int idx = min - ttyDrivers[i].minorFrom;
-      struct stat sstat;
+      struct stat sb;
       char* fullPath;
       for (;;) {
          xAsprintf(&fullPath, "%s/%d", ttyDrivers[i].path, idx);
-         int err = stat(fullPath, &sstat);
-         if (err == 0 && major(sstat.st_rdev) == maj && minor(sstat.st_rdev) == min) {
+         int err = stat(fullPath, &sb);
+         if (err == 0 && major(sb.st_rdev) == maj && minor(sb.st_rdev) == min) {
             return fullPath;
          }
          free(fullPath);
 
          xAsprintf(&fullPath, "%s%d", ttyDrivers[i].path, idx);
-         err = stat(fullPath, &sstat);
-         if (err == 0 && major(sstat.st_rdev) == maj && minor(sstat.st_rdev) == min) {
+         err = stat(fullPath, &sb);
+         if (err == 0 && major(sb.st_rdev) == maj && minor(sb.st_rdev) == min) {
             return fullPath;
          }
          free(fullPath);
@@ -1372,8 +1372,8 @@ static char* LinuxProcessTable_updateTtyDevice(TtyDriver* ttyDrivers, unsigned l
 
          idx = min;
       }
-      int err = stat(ttyDrivers[i].path, &sstat);
-      if (err == 0 && tty_nr == sstat.st_rdev) {
+      int err = stat(ttyDrivers[i].path, &sb);
+      if (err == 0 && tty_nr == sb.st_rdev) {
          return xStrdup(ttyDrivers[i].path);
       }
    }