fix(spm_common): fix comparison that is always true

This comparison always evaluates to true. I assume it was a typo when
copy and pasting a line.

Signed-off-by: Karl Meakin <karl.meakin@arm.com>
Change-Id: I90d8a33b3a9b4ac0aabc9cafa11b5b705ef1aab0
1 file changed