[SCSI] lpfc: Fix wrong assignment in lpfc_debugfs.c

On lpfc_debugfs_initialize function the dumpHostSlim member setup happens
when 'phba->sli_rev < LPFC_SLI_REV4' is true, however when it is false NULL
has been assigned to debug_dumpHBASlim instead of debug_dumpHostSlim.

Signed-off-by: Felipe Pena <felipensp@gmail.com>
Acked-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>