io_uring/cmd: axe duplicate io_uring_cmd_import_fixed_vec() declaration

io_uring_cmd_import_fixed_vec() is declared in both
include/linux/io_uring/cmd.h and io_uring/uring_cmd.h. The declarations
are identical (if redundant) for CONFIG_IO_URING=y. But if
CONFIG_IO_URING=N, include/linux/io_uring/cmd.h declares the function as
static inline while io_uring/uring_cmd.h declares it as extern. This
causes linker errors if the declaration in io_uring/uring_cmd.h is used.

Remove the declaration in io_uring/uring_cmd.h to avoid linker errors
and prevent the declarations getting out of sync.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: ef49027 ("io_uring/cmd: introduce io_uring_cmd_import_fixed_vec")
Link: https://lore.kernel.org/r/20250520193337.1374509-1-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: calebsander

io_uring/uring_cmd.h

@@ -17,9 +17,3 @@ bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
 				   struct io_uring_task *tctx, bool cancel_all);
 
 void io_cmd_cache_free(const void *entry);
-
-int io_uring_cmd_import_fixed_vec(struct io_uring_cmd *ioucmd,
-				  const struct iovec __user *uvec,
-				  size_t uvec_segs,
-				  int ddir, struct iov_iter *iter,
-				  unsigned issue_flags);