scsi: lpfc: avoid false-positive gcc-8 warning

This is an interesting regression with gcc-8, showing a harmless warning
for correct code:

In file included from include/linux/kernel.h:13:0,
                 ...
                 from drivers/scsi/lpfc/lpfc_debugfs.c:23:
include/linux/printk.h:301:2: error: 'eq' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
  ^~~~~~
In file included from drivers/scsi/lpfc/lpfc_debugfs.c:58:0:
drivers/scsi/lpfc/lpfc_debugfs.h:451:31: note: 'eq' was declared here

I managed to reduce the warning into a small test case for gcc-8 that I
reported in the gcc bugzilla[1].

As a workaround, this changes the logic to move the two assignments of
'eq' out of the conditions and instead make the index conditional.  This
works for all configurations I tried and avoids adding a bogus
initialization.

Acked-by: James Smart <james.smart@broadcom.com>
Link: [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81958


Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>