[Makefile] [Linter] Correct regex bug
[Makefile] [Linter] Correct regex bug

Aside from being incorrect, this one led to a catastrophic (i.e. more
than a fraction of a second) run time on one of the source files.

CylonicRaider/Instant,CylonicRaider/Instant,CylonicRaider/Instant,CylonicRaider/Instant,CylonicRaider/Instant