msm: smd: change bounds check on smd edges

Off-by-one array bounds checking could result in out-of-bounds array
access.

Correct array bounds checking.

CRs-Fixed: 561670
Change-Id: Ie20396444686a8ce203c2296ba7235514279f35d
Signed-off-by: Brent Hronik <bhronik@codeaurora.org>