libbio: add casts to eliminate -Wconversion warning

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/87140044

diff --git a/src/libbio/bgetc.c b/src/libbio/bgetc.c
index 3399fb16b310b433f373af1b6ed6ae922c37d810..ceb5cb13f8c75eabf111f325c7fe0e1e25c91945 100644 (file)
--- a/src/libbio/bgetc.c
+++ b/src/libbio/bgetc.c
@@ -83,7 +83,7 @@ Bgetle4(Biobuf *bp)
 
        l = Bgetle2(bp);
        h = Bgetle2(bp);
-       return l|((uint32)h<<16);
+       return (int)((uint32)l|((uint32)h<<16));
 }
 
 int