Fix the conflict between rwpidforward and rw mount options

Both these options are started with "rw" - that's why the first one
isn't switched on even if it is specified. Fix this by adding a length
check for "rw" option check.

Cc: <stable@kernel.org>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

fs/cifs/connect.c

@@ -1298,7 +1298,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 			/* ignore */
 		} else if (strnicmp(data, "guest", 5) == 0) {
 			/* ignore */
-		} else if (strnicmp(data, "rw", 2) == 0) {
+		} else if (strnicmp(data, "rw", 2) == 0 && strlen(data) == 2) {
 			/* ignore */
 		} else if (strnicmp(data, "ro", 2) == 0) {
 			/* ignore */
@@ -1401,7 +1401,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 			vol->server_ino = 1;
 		} else if (strnicmp(data, "noserverino", 9) == 0) {
 			vol->server_ino = 0;
-		} else if (strnicmp(data, "rwpidforward", 4) == 0) {
+		} else if (strnicmp(data, "rwpidforward", 12) == 0) {
 			vol->rwpidforward = 1;
 		} else if (strnicmp(data, "cifsacl", 7) == 0) {
 			vol->cifs_acl = 1;