libselinux: use correct name and content for patch 0004

Commit 6288409642d8368104f916bd264d2cb042942dfa ("libselinux: add
patch to fix build with gcc < 4.7") introduced a patch, but its file
name was incorrect, so it was never applied. In addition, the patch
was generated against the Git repository of SELinux, which includes
all projects, and therefore it doesn't apply to the libselinux source
code extracted from the tarball: the "libselinux/" component path
needs to be removed from the patch.

This commit fixes both problems, which should finally and really fix:

  http://autobuild.buildroot.net/results/c3272566bb808e43bb77ec59cfe596f7e0fe9a64/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit cb8d1743cab1449b91afbabe38c64cbb85bef6ba)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libselinux/0004-Fix-build-break-around-__atomic_-with-GCC-4.7.patch

@@ -14,13 +14,13 @@ pthread_mutex_unlock() "synchronize memory with respect to other threads"...)
 
 Signed-off-by: Hollis Blanchard <hollis_blanchard@mentor.com>
 ---
- libselinux/src/label_file.h | 18 ++++++++++++++++++
+ src/label_file.h | 18 ++++++++++++++++++
  1 file changed, 18 insertions(+)
 
-diff --git a/libselinux/src/label_file.h b/libselinux/src/label_file.h
+diff --git a/src/label_file.h b/src/label_file.h
 index 2fa85474..47859baf 100644
---- a/libselinux/src/label_file.h
-+++ b/libselinux/src/label_file.h
+--- a/src/label_file.h
++++ b/src/label_file.h
 @@ -351,8 +351,14 @@ static inline int compile_regex(struct saved_data *data, struct spec *spec,
  	 * init_routine does not take a parameter, it's not possible
  	 * to use, so we generate the same effect with atomics and a