kernel: explicitly include required header files under kernel/

Following an experimental deletion of the unnecessary directive

 #include <linux/slab.h>

from the header file <linux/percpu.h>, these files under kernel/ were exposed
as needing to include one of <linux/slab.h> or <linux/gfp.h>, so explicit
includes were added where necessary.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/irq/devres.c

 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/device.h>
+#include <linux/gfp.h>
 
 /*
  * Device resource management aware IRQ request/free implementation.

kernel/irq/manage.c

@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/random.h>
 #include <linux/interrupt.h>
+#include <linux/slab.h>
 
 #include "internals.h"
 

kernel/marker.c

@@ -23,6 +23,7 @@
 #include <linux/rcupdate.h>
 #include <linux/marker.h>
 #include <linux/err.h>
+#include <linux/slab.h>
 
 extern struct marker __start___markers[];
 extern struct marker __stop___markers[];

kernel/ns_cgroup.c

@@ -7,6 +7,7 @@
 #include <linux/module.h>
 #include <linux/cgroup.h>
 #include <linux/fs.h>
+#include <linux/slab.h>
 
 struct ns_cgroup {
 	struct cgroup_subsys_state css;

kernel/rcutorture.c

@@ -45,6 +45,7 @@
 #include <linux/byteorder/swabb.h>
 #include <linux/stat.h>
 #include <linux/srcu.h>
+#include <linux/slab.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "

kernel/res_counter.c

@@ -10,6 +10,7 @@
 #include <linux/types.h>
 #include <linux/parser.h>
 #include <linux/fs.h>
+#include <linux/slab.h>
 #include <linux/res_counter.h>
 #include <linux/uaccess.h>
 

kernel/time.c

@@ -35,6 +35,7 @@
 #include <linux/syscalls.h>
 #include <linux/security.h>
 #include <linux/fs.h>
+#include <linux/slab.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>

kernel/user_namespace.c

@@ -8,6 +8,7 @@
 #include <linux/module.h>
 #include <linux/version.h>
 #include <linux/nsproxy.h>
+#include <linux/slab.h>
 #include <linux/user_namespace.h>
 
 /*

kernel/utsname.c

@@ -14,6 +14,7 @@
 #include <linux/utsname.h>
 #include <linux/version.h>
 #include <linux/err.h>
+#include <linux/slab.h>
 
 /*
  * Clone a new ns copying an original utsname, setting refcount to 1