nand-part: Avoid Linux-only ioctl() on other platforms

The nand-part.c code tries to re-read the partition tables
by issuing an ioctl(fd, BLKRRPART, NULL). This isn't available
on non-Linux platforms, e.g. Mac OS X.

Add preprocessor conditionals to prevent this from breaking
the build.
Signed-off-by: Bernhard Nortmann <bernhard.nortmann@web.de>

nand-part.c

@@ -50,8 +50,10 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <string.h>
-#include <sys/ioctl.h>
-#include <sys/mount.h> /* BLKRRPART */
+#ifdef __linux__
+# include <sys/ioctl.h>
+# include <sys/mount.h> /* BLKRRPART */
+#endif
 #include "nand-common.h"
 
 // so far, only known formats are for A10 and A20
@@ -249,8 +251,10 @@ static int writembrs(int fd, char names[][MAX_NAME], __u32 start, __u32 *lens, u
 		write(fd,mbr,MBR_SIZE);
 	}
 
+#ifdef __linux__
 	if (ioctl(fd, BLKRRPART, NULL))
 		perror("Failed rereading partition table");
+#endif
 
 	return 1;
 }
@@ -312,7 +316,9 @@ int nand_part (int argc, char **argv, const char *cmd, int fd, int force)
 		if (writembrs(fd, names, start, lens, user_types, argc, partoffset, force)) {
 			printf("\nverifying new partition tables:\n");
 			checkmbrs(fd);
+#ifdef __linux__
 			printf("rereading partition table... returned %d\n", ioctl(fd, BLKRRPART, 0));
+#endif
 		}
 	}
 	close(fd);