WasmFS JS API: Clean up API Wrappers (#19605)

This PR removes the unnecessary if statements in the JS API, since the
syscalls do not actually set errno. This PR does not change any functionality
of the API wrapper methods.

Author: jameshu15869

system/lib/wasmfs/js_api.cpp

@@ -126,19 +126,11 @@ int _wasmfs_mkdir(char* path, int mode) {
 int _wasmfs_rmdir(char* path){ return __syscall_unlinkat(AT_FDCWD, (intptr_t)path, AT_REMOVEDIR); }
 
 int _wasmfs_open(char* path, int flags, mode_t mode) {
-  int err = __syscall_openat(AT_FDCWD, (intptr_t)path, flags, mode);
-  if (err == -1) {
-    return -errno;
-  }
-  return err;
+  return __syscall_openat(AT_FDCWD, (intptr_t)path, flags, mode);
 }
 
 int _wasmfs_mknod(char* path, mode_t mode, dev_t dev) {
-  int err = __syscall_mknodat(AT_FDCWD, (intptr_t)path, mode, dev);
-  if (err == -1) {
-    return errno;
-  }
-  return err;
+  return __syscall_mknodat(AT_FDCWD, (intptr_t)path, mode, dev);
 }
 
 int _wasmfs_unlink(char* path) {
@@ -190,11 +182,7 @@ int _wasmfs_lchmod(char* path, mode_t mode) {
 }
 
 int _wasmfs_rename(char* oldpath, char* newpath) {
-  int err = __syscall_renameat(AT_FDCWD, (intptr_t)oldpath, AT_FDCWD, (intptr_t)newpath);
-  if (err == -1) {
-    return errno;
-  }
-  return err;
+  return __syscall_renameat(AT_FDCWD, (intptr_t)oldpath, AT_FDCWD, (intptr_t)newpath);
 };
 
 int _wasmfs_read(int fd, void *buf, size_t count) {
@@ -228,19 +216,11 @@ int _wasmfs_close(int fd) {
 }
 
 int _wasmfs_stat(char* path, struct stat* statBuf) {
-  int err = __syscall_stat64((intptr_t)path, (intptr_t)statBuf);
-  if (err == -1) {
-    return errno;
-  }
-  return err;
+  return __syscall_stat64((intptr_t)path, (intptr_t)statBuf);
 }
 
 int _wasmfs_lstat(char* path, struct stat* statBuf) {
-  int err = __syscall_lstat64((intptr_t)path, (intptr_t)statBuf);
-  if (err == -1) {
-    return errno;
-  }
-  return err;
+  return __syscall_lstat64((intptr_t)path, (intptr_t)statBuf);
 }
 
 // Helper method that identifies what a path is: