Fix missing closing bracket in FcStrIsAbsoluteFilename()

Fixes https://gitlab.freedesktop.org/fontconfig/fontconfig/issues/96
diff --git a/src/fcstr.c b/src/fcstr.c
index bfddd68..4247c85 100644
--- a/src/fcstr.c
+++ b/src/fcstr.c
@@ -872,7 +872,7 @@
 {
 #ifdef _WIN32
     if (*s == '\\' ||
-	(isalpha (*s) && s[1] == ':' && (s[2] == '/' || s[2] == '\\'))
+	(isalpha (*s) && s[1] == ':' && (s[2] == '/' || s[2] == '\\')))
 	return FcTrue;
 #endif
     return *s == '/';