diff.c: remove duplicate bibtex pattern introduced by merge 92bb9785
diff.c: remove duplicate bibtex pattern introduced by merge 92bb9785

Signed-off-by: Brandon Casey <77bc9a9984e6786c5799d7a71768cf023120ef76@nrlssc.navy.mil>
Signed-off-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git