raid6/algos.c : bug fix : Add the missing definitions to the pq.h file

Adding these pr_info and pr_err definitions so as to allow code to be
compiled successfully for testing in userspace, since the printk has
been replaced by pr_info and pr_err in algos.c

Absence of these definitions result in the compilation errors
such as ' undefined reference to `pr_info' ' ' undefined reference to
`pr_err' '

Cc: NeilBrown <neilb@suse.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NGayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: NShaohua Li <shli@fb.com>

include/linux/raid/pq.h

@@ -152,6 +152,8 @@ void raid6_dual_recov(int disks, size_t bytes, int faila, int failb,
 
 # define jiffies	raid6_jiffies()
 # define printk 	printf
+# define pr_err(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
+# define pr_info(format, ...) fprintf(stdout, format, ## __VA_ARGS__)
 # define GFP_KERNEL	0
 # define __get_free_pages(x, y)	((unsigned long)mmap(NULL, PAGE_SIZE << (y), \
 						     PROT_READ|PROT_WRITE,   \