Cleaup read() and write() variants, plus a couple of new functions like
xlseek and fdlength() for the new mkswap.
diff --git a/miscutils/rx.c b/miscutils/rx.c
index cff5a62..41673b6 100644
--- a/miscutils/rx.c
+++ b/miscutils/rx.c
@@ -212,7 +212,7 @@
 		wantBlockNo++;
 		length += blockLength;
 
-		if (bb_full_write(filefd, blockBuf, blockLength) < 0) {
+		if (full_write(filefd, blockBuf, blockLength) < 0) {
 			note_error("write to file failed: %m");
 			goto fatal;
 		}