drivers/md: use time_before, time_before_eq, etc

The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.

A simplified version of the semantic patch making this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@ change_compare_np @
expression E;
@@

(
- jiffies <= E
+ time_before_eq(jiffies,E)
|
- jiffies >= E
+ time_after_eq(jiffies,E)
|
- jiffies < E
+ time_before(jiffies,E)
|
- jiffies > E
+ time_after(jiffies,E)
)

@ include depends on change_compare_np @
@@

#include <linux/jiffies.h>

@ no_include depends on !include && change_compare_np @
@@

  #include <linux/...>
+ #include <linux/jiffies.h>
// </smpl>

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NJulia Lawall <julia@diku.dk>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/md/raid6algos.c

@@ -121,7 +121,8 @@ int __init raid6_select_algo(void)
 			j0 = jiffies;
 			while ( (j1 = jiffies) == j0 )
 				cpu_relax();
-			while ( (jiffies-j1) < (1 << RAID6_TIME_JIFFIES_LG2) ) {
+			while (time_before(jiffies,
+					    j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
 				(*algo)->gen_syndrome(disks, PAGE_SIZE, dptrs);
 				perf++;
 			}