find_filesystem(): simplify comparison

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/filesystems.c b/fs/filesystems.c
index 5797d45..c5618db 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -46,9 +46,9 @@
 static struct file_system_type **find_filesystem(const char *name, unsigned len)
 {
 	struct file_system_type **p;
-	for (p=&file_systems; *p; p=&(*p)->next)
-		if (strlen((*p)->name) == len &&
-		    strncmp((*p)->name, name, len) == 0)
+	for (p = &file_systems; *p; p = &(*p)->next)
+		if (strncmp((*p)->name, name, len) == 0 &&
+		    !(*p)->name[len])
 			break;
 	return p;
 }