input: Make preadbuffer static

The function preadbuffer should be static as it's only used in
input.c.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

src/input.c

diff --git a/src/input.c b/src/input.c
index f11ac84..aa5dcfc 100644
--- a/src/input.c
+++ b/src/input.c
@@ -109,6 +109,7 @@
 STATIC void pushfile(void);
 static int preadfd(void);
 static void setinputfd(int fd, int push);
+static int preadbuffer(void);
 
 #ifdef mkinit
 INCLUDE <stdio.h>
@@ -222,8 +223,7 @@
  * 4) Process input up to the next newline, deleting nul characters.
  */
 
-int
-preadbuffer(void)
+static int preadbuffer(void)
 {
 	char *q;
 	int more;

src/input.h

diff --git a/src/input.h b/src/input.h
index 775291b..90ff6c3 100644
--- a/src/input.h
+++ b/src/input.h
@@ -52,7 +52,6 @@
 
 int pgetc(void);
 int pgetc2(void);
-int preadbuffer(void);
 void pungetc(void);
 void pushstring(char *, void *);
 void popstring(void);