scsi: lpfc: Fix stack trace seen while setting rrq active

Call traces have been observed running different tests that involve aborts
and setting the rrq active flag.  The lpfc_set_rrq_active routine is doing
a mempool_alloc under the soft_irq processing level. When the mempool needs
to get a new buffer from the free pool and has to wait for memory to become
free it will check the flags passed in on the alloc and dump the stack if
the thread is running in interrupt context.

Replace the GFP_KERNEL flag with GFP_ATOMIC so that the memory allocation
will not attempt to sleep if there is no mem available.

Link: https://lore.kernel.org/r/20200630215001.70793-7-jsmart2021@gmail.com


Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>