[klibc] [PATCH 2/2] mount_main: Fix empty string check

[Benjamin Drung]

gcc 7.3.0 complains:

```
usr/utils/mount_main.c: In function ‘print_mount’:
usr/utils/mount_main.c:46:46: warning: comparison between pointer and zero character constant [-Wpointer-compare]
   if (mnt->mnt_type != NULL && mnt->mnt_type != '\0')
                                              ^~
usr/utils/mount_main.c:46:32: note: did you mean to dereference the pointer?
   if (mnt->mnt_type != NULL && mnt->mnt_type != '\0')
                                ^
usr/utils/mount_main.c:48:46: warning: comparison between pointer and zero character constant [-Wpointer-compare]
   if (mnt->mnt_opts != NULL && mnt->mnt_opts != '\0')
                                              ^~
usr/utils/mount_main.c:48:32: note: did you mean to dereference the pointer?
   if (mnt->mnt_opts != NULL && mnt->mnt_opts != '\0')
                                ^
```
---
 usr/utils/mount_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/usr/utils/mount_main.c b/usr/utils/mount_main.c
index ab3cb718..0d299c43 100644
--- a/usr/utils/mount_main.c
+++ b/usr/utils/mount_main.c
@@ -43,9 +43,9 @@ static __noreturn print_mount(char *type)
 		if (type && mnt->mnt_type && strcmp(type, mnt->mnt_type))
 			continue;
 		printf("%s on %s", mnt->mnt_fsname, mnt->mnt_dir);
-		if (mnt->mnt_type != NULL && mnt->mnt_type != '\0')
+		if (mnt->mnt_type != NULL && *mnt->mnt_type != '\0')
 			printf(" type %s", mnt->mnt_type);
-		if (mnt->mnt_opts != NULL && mnt->mnt_opts != '\0')
+		if (mnt->mnt_opts != NULL && *mnt->mnt_opts != '\0')
 			printf(" (%s)", mnt->mnt_opts);
 		printf("\n");
 	}
-- 
2.17.1