Drop paths.h include

We include the file in plenty of places. This is mostly due to
historical reasons. The only place that needs something from the
header file is storage_backend_fs which opens _PATH_MOUNTED. But
it gets the file included indirectly via mntent.h. At no other
place in our code we need _PATH_.*. Drop the include and
configure check then.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

tests/testutils.c

@@ -54,10 +54,6 @@
 # endif
 #endif
 
-#ifdef HAVE_PATHS_H
-# include <paths.h>
-#endif
-
 #define VIR_FROM_THIS VIR_FROM_NONE
 
 VIR_LOG_INIT("tests.testutils");