staging: lustre: fid: avoid false-positive uninitialized variable warning

One of Neil's recent cleanups apparently has led the code to get
to a state where gcc tracks the 'seqnr' variable just enough to
see that it is sometimes initialized in seq_client_alloc_seq(),
but not enough that it can prove this initialization to be reliable
before the use of that variable:

drivers/staging/lustre/lustre/fid/fid_request.c: In function 'seq_client_alloc_fid':
drivers/staging/lustre/lustre/fid/fid_request.c:245:22: error: 'seqnr' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The code seems to be otherwise correct, and I could not come
up with a good way to simplify it further, so this adds a fake
initialization to shut up that warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/fid/fid_request.c

@@ -174,6 +174,7 @@ static int seq_client_alloc_seq(const struct lu_env *env,
 		if (rc) {
 			CERROR("%s: Can't allocate new meta-sequence, rc %d\n",
 			       seq->lcs_name, rc);
+			*seqnr = U64_MAX;
 			return rc;
 		}
 		CDEBUG(D_INFO, "%s: New range - " DRANGE "\n",