NFS: Fix up new minorversion= option

The new minorversion= mount option (commit 3fd5be9e) was merged at
the same time as the recent sloppy parser fixes (commit a5a16bae),
so minorversion= still uses the old value parsing logic.

If the minorversion= option specifies a bogus value, it should fail
with "bad value" not "bad option."

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 0b4cbdc..83a3107 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -158,7 +158,7 @@
 	{ Opt_mountvers, "mountvers=%s" },
 	{ Opt_nfsvers, "nfsvers=%s" },
 	{ Opt_nfsvers, "vers=%s" },
-	{ Opt_minorversion, "minorversion=%u" },
+	{ Opt_minorversion, "minorversion=%s" },
 
 	{ Opt_sec, "sec=%s" },
 	{ Opt_proto, "proto=%s" },
@@ -1001,7 +1001,6 @@
 	while ((p = strsep(&raw, ",")) != NULL) {
 		substring_t args[MAX_OPT_ARGS];
 		unsigned long option;
-		int int_option;
 		int token;
 
 		if (!*p)
@@ -1273,11 +1272,16 @@
 			}
 			break;
 		case Opt_minorversion:
-			if (match_int(args, &int_option))
-				return 0;
-			if (int_option < 0 || int_option > NFS4_MAX_MINOR_VERSION)
-				return 0;
-			mnt->minorversion = int_option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			if (option > NFS4_MAX_MINOR_VERSION)
+				goto out_invalid_value;
+			mnt->minorversion = option;
 			break;
 
 		/*