Fix 1989/ovdluhe/Makefile for clang in linux

Makefile:90: *** recipe commences before first target.  Stop.

This happened due to a typo which left off a \ before a newline where
it is meant to be one line.

1989/ovdluhe/Makefile

@@ -86,7 +86,7 @@ CC= cc
 ifeq ($(CC),clang)
 #
 CSILENCE+= -Wno-comma -Wno-implicit-int-conversion -Wno-missing-prototypes \
-	-Wno-missing-variable-declarations -Wno-poison-system-directories
+	-Wno-missing-variable-declarations -Wno-poison-system-directories \
 	-Wno-sign-conversion -Wno-strict-prototypes
 #
 CWARN+= -Weverything