Tidy up includes and copyright notices, fix indentation

The files not mentioned in changelog below had only
copyright notices fixes and indentation fixes.

* defs.h: Include <stdint.h> and <inttypes.h>.
* file.c: Do not include <inttypes.h>.
Move struct kernel_dirent declaration below top include block.
* block.c: Do not include <stdint.h> and <inttypes.h>.
* quota.c: Likewise.
* desc.c: Likewise.
* signal.c: Likewise.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/pathtrace.c b/pathtrace.c
index d50b268..87d9827 100644
--- a/pathtrace.c
+++ b/pathtrace.c
@@ -27,14 +27,12 @@
  */
 
 #include "defs.h"
-
 #include <sys/param.h>
-
 #ifdef HAVE_POLL_H
-#include <poll.h>
+# include <poll.h>
 #endif
 #ifdef HAVE_SYS_POLL_H
-#include <sys/poll.h>
+# include <sys/poll.h>
 #endif
 
 #include "syscall.h"