package/lmbench: mark scripts/build as bash script

scripts/build makes use of the "+=" operator which is not supported by
a pure POSIX shell. We switch to /bin/bash in order to avoid errors of
the form:

    ../scripts/build: 21: ../scripts/build: LDLIBS+= -lm: not found

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 037d5ffcb67dc72d37db7a0383145e9e99b36fc7)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/lmbench/0001-scripts-build-use-bin-bash-as-shell.patch

@@ -0,0 +1,28 @@
+From 02a538c2b4b54b41d23dbd7668714ea4d2016131 Mon Sep 17 00:00:00 2001
+From: Markus Mayer <mmayer@broadcom.com>
+Date: Thu, 13 Jun 2019 12:27:04 -0700
+Subject: [PATCH] scripts/build: use /bin/bash as shell
+
+scripts/build makes use of the "+=" operator which is not supported by
+/bin/sh. We switch to /bin/bash in order to avoid errors of the form
+
+    ../scripts/build: 21: ../scripts/build: LDLIBS+= -lm: not found
+
+Signed-off-by: Markus Mayer <mmayer@broadcom.com>
+---
+ scripts/build | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/scripts/build b/scripts/build
+index 34a1371d0056..60b755cd2320 100755
+--- a/scripts/build
++++ b/scripts/build
+@@ -1,4 +1,4 @@
+-#!/bin/sh
++#!/bin/bash
+ 
+ CC=${CC-`../scripts/compiler`}
+ MAKE=${MAKE-`../scripts/make`}
+-- 
+2.17.1
+