[klibc] Add trivial lseek test

Add a trivial lseek test which should at least make it possible to
catch parameter marshalling errors when converting to llseek.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/usr/klibc/tests/Kbuild b/usr/klibc/tests/Kbuild
index 22b2078..d7f1d51 100644
--- a/usr/klibc/tests/Kbuild
+++ b/usr/klibc/tests/Kbuild
@@ -21,6 +21,7 @@
 getpagesize.shared-y	:= getpagesize.o
 hello.shared-y		:= hello.o
 idtest.shared-y		:= idtest.o
+lseek.shared-y		:= lseek.o
 malloctest.shared-y	:= malloctest.o
 malloctest2.shared-y	:= malloctest2.o
 memstrtest.shared-y	:= memstrtest.o
diff --git a/usr/klibc/tests/lseek.c b/usr/klibc/tests/lseek.c
new file mode 100644
index 0000000..c4e7f54
--- /dev/null
+++ b/usr/klibc/tests/lseek.c
@@ -0,0 +1,15 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+int main(void)
+{
+  int fd = open("test.out", O_RDWR|O_CREAT|O_TRUNC, 0666);
+  off_t rv;
+
+  rv = lseek(fd, 123456789012ULL, SEEK_SET);
+
+  printf("seek to: %lld\n", rv);
+  return 0;
+}