Remove local malloc prototypes, which are incorrect and conflict with

both GCC builtin and system declared ones.

usr.bin/window/context.c

@@ -49,8 +49,6 @@ static char rcsid[] =
  * Context push/pop for nested command files.
  */
 
-char *malloc();
-
 cx_alloc()
 {
 	register struct context *xp;

usr.bin/window/string.c

@@ -43,8 +43,6 @@ static char rcsid[] =
 #include <string.h> /* System string definitions. */
 #include "mystring.h" /* Local string definitions. */
 
-char *malloc();
-
 char *
 str_cpy(s)
 register char *s;

usr.bin/window/tttermcap.c

@@ -44,7 +44,6 @@ static char rcsid[] =
 
 char *tgetstr();
 char *tgoto();
-char *malloc();
 
 tttputc(c)
 {

usr.bin/window/var.c

@@ -44,8 +44,6 @@ static char rcsid[] =
 #include "var.h"
 #include "mystring.h"
 
-char *malloc();
-
 struct var *
 var_set1(head, name, v)
 struct var **head;