[SCSI] sym2: Remove last vestiges of sym_sniff_inquiry

The SYM_OPT_SNIFF_INQUIRY define is never set any more, and the
sym_sniff_inquiry() function doesn't exist

From: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>