unix/linux: update Dockerfile to Go 1.15.4

No changes in generated files.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Change-Id: Ibbb81f8ef48d43d7fb620fec57c3ac779ebf0e11
Reviewed-on: https://go-review.googlesource.com/c/sys/+/268357
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
diff --git a/unix/linux/Dockerfile b/unix/linux/Dockerfile
index 3878110..f7ab8e5 100644
--- a/unix/linux/Dockerfile
+++ b/unix/linux/Dockerfile
@@ -21,9 +21,9 @@
 RUN git clone --branch release/2.32/master --depth 1 git://sourceware.org/git/glibc.git
 
 # Get Go
-ENV GOLANG_VERSION 1.15.3
+ENV GOLANG_VERSION 1.15.4
 ENV GOLANG_DOWNLOAD_URL https://golang.org/dl/go$GOLANG_VERSION.linux-amd64.tar.gz
-ENV GOLANG_DOWNLOAD_SHA256 010a88df924a81ec21b293b5da8f9b11c176d27c0ee3962dc1738d2352d3c02d
+ENV GOLANG_DOWNLOAD_SHA256 eb61005f0b932c93b424a3a4eaa67d72196c79129d9a3ea8578047683e2c80d5
 
 RUN curl -fsSL "$GOLANG_DOWNLOAD_URL" -o golang.tar.gz \
     && echo "$GOLANG_DOWNLOAD_SHA256  golang.tar.gz" | sha256sum -c - \