file_ioctl.c: fix build on systems without <linux/fiemap.h>

* configure.ac (AC_CHECK_HEADERS): Add linux/fiemap.h.
* file_ioctl.c: Do not include <linux/fiemap.h> and xlat/fiemap_*.h
if [!HAVE_LINUX_FIEMAP_H].
(file_ioctl): Do not parse FS_IOC_FIEMAP if [!HAVE_LINUX_FIEMAP_H].
diff --git a/configure.ac b/configure.ac
index 6d2d148..c3c556e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -363,6 +363,7 @@
 	inttypes.h
 	linux/bsg.h
 	linux/falloc.h
+	linux/fiemap.h
 	linux/filter.h
 	linux/hiddev.h
 	linux/ip_vs.h