Replace uses of "git-var" with "git var"

Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/git-am.sh b/git-am.sh
index 6aa8192..8f91a97 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -291,7 +291,7 @@
 ws=`cat "$dotest/whitespace"`
 if test "$(cat "$dotest/sign")" = t
 then
-	SIGNOFF=`git-var GIT_COMMITTER_IDENT | sed -e '
+	SIGNOFF=`git var GIT_COMMITTER_IDENT | sed -e '
 			s/>.*/>/
 			s/^/Signed-off-by: /'
 		`