scsi: ufs: Fix register dump caused sleep in atomic context

ufshcd_print_host_regs() can be called by interrupt handler, but it may
sleep due to ufshcd_dump_regs() allocates the dump buffer memory with flag
GFP_KERNEL. Fix it by changing GFP_KERNEL to GFP_ATMOIC.

Link: https://lore.kernel.org/r/1573798172-20534-5-git-send-email-cang@codeaurora.org
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -117,7 +117,7 @@ int ufshcd_dump_regs(struct ufs_hba *hba, size_t offset, size_t len,
 	if (offset % 4 != 0 || len % 4 != 0) /* keep readl happy */
 		return -EINVAL;
 
-	regs = kzalloc(len, GFP_KERNEL);
+	regs = kzalloc(len, GFP_ATOMIC);
 	if (!regs)
 		return -ENOMEM;