ncurses: Fix -Wunterminated-string-initialization

This was fixed in upstream ncurses (https://ncurses.scripts.mit.edu/?p=ncurses.git;a=commitdiff;h=64afa9627b292b87c8473928854f3dd8c463d833),
but for now only pull in the minimal fix that avoids reading
beyond the end of the buffer during strlen().

MFC after:	3 days

Author: arichardson

contrib/ncurses/progs/infocmp.c

@@ -687,7 +687,7 @@ compare_predicate(PredType type, PredIdx idx, const char *name)
 #define DATAX()        DATA("", "")
 
 typedef struct {
-    const char from[4];
+    const char from[8];
     const char to[12];
 } assoc;