Revert "posix: device_io: implement fileno()"

This reverts commit 48dff55.

PR zephyrproject-rtos#73978 introduced a regression.
Unfortunately this PR cannot be reverted without reverting also
Let's revert both PRs to stabilize main again towards the 3.7 release.

For more details on the issue see
zephyrproject-rtos#75205

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

lib/os/fdtable.c

@@ -414,16 +414,6 @@ FILE *zvfs_fdopen(int fd, const char *mode)
 	return (FILE *)&fdtable[fd];
 }
 
-int zvfs_fileno(FILE *file)
-{
-	if (!IS_ARRAY_ELEMENT(fdtable, file)) {
-		errno = EBADF;
-		return -1;
-	}
-
-	return (struct fd_entry *)file - fdtable;
-}
-
 int zvfs_fstat(int fd, struct stat *buf)
 {
 	if (_check_fd(fd) < 0) {

lib/posix/options/device_io.c

@@ -15,7 +15,6 @@
 /* prototypes for external, not-yet-public, functions in fdtable.c or fs.c */
 int zvfs_close(int fd);
 FILE *zvfs_fdopen(int fd, const char *mode);
-int zvfs_fileno(FILE *file);
 int zvfs_open(const char *name, int flags);
 ssize_t zvfs_read(int fd, void *buf, size_t sz, size_t *from_offset);
 ssize_t zvfs_write(int fd, const void *buf, size_t sz, size_t *from_offset);
@@ -53,11 +52,6 @@ FILE *fdopen(int fd, const char *mode)
 	return zvfs_fdopen(fd, mode);
 }
 
-int fileno(FILE *file)
-{
-	return zvfs_fileno(file);
-}
-
 int open(const char *name, int flags, ...)
 {
 	/* FIXME: necessarily need to check for O_CREAT and unpack ... if set */