lib9: move seek into open.c

More preparation for opendir.

src/lib9/mkfile

@@ -139,7 +139,6 @@ LIB9OFILES=\
 	readn.$O\
 	rfork.$O\
 	searchpath.$O\
-	seek.$O\
 	sendfd.$O\
 	sleep.$O\
 	strdup.$O\

src/lib9/open.c

@@ -129,13 +129,18 @@ p9open(char *name, int mode)
 	return fd;
 }
 
+vlong
+p9seek(int fd, vlong offset, int whence)
+{
+	return lseek(fd, offset, whence);
+}
+
 int
 p9close(int fd)
 {
 	return close(fd);
 }
 
-
 extern int _p9dir(struct stat*, struct stat*, char*, Dir*, char**, char*);
 
 #if defined(__linux__)

src/lib9/seek.c

@@ -1,8 +0,0 @@
-#include <u.h>
-#include <libc.h>
-
-vlong
-seek(int fd, vlong offset, int whence)
-{
-	return lseek(fd, offset, whence);
-}