klibc - Jan 2019 - [klibc:master] mount_main: Fix empty string check

Commit-ID:  56bfd58fdce4fc32a2be2981655252840c9c02cb
Gitweb:    
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=56bfd58fdce4fc32a2be2981655252840c9c02cb
Author:     Benjamin Drung <benjamin.drung at profitbricks.com>
AuthorDate: Wed, 13 Jun 2018 11:48:39 +0200
Committer:  Ben Hutchings <ben at decadent.org.uk>
CommitDate: Wed, 2 Jan 2019 03:08:04 +0000

[klibc] mount_main: Fix empty string check

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')
                                ^
```

Link: https://www.zytor.com/pipermail/klibc/2018-June/003994.html
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

---
 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 ab3cb71..0d299c4 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");
 	}