libtool-cross/native: Force usage of bash due to sstate inconsistencies

Scenario:
a) libtool script is built on system with bash as /bin/sh
b) machine B installs sstate from build a)
c) machine B has dash as /bin/sh

In this scenario, the script fails to work properly since its expecting
/bin/sh to have bash like syntax and it no longer does have it.

This patch forces the configure process to use /bin/bash, not /bin/sh
and hence allows the scripts to work correctly when used from sstate.

(From OE-Core rev: 24d5b449e5f4d91119f0d8e13c457618811aadfc)

(From OE-Core rev: 330c3085317a0b0981163ff5c41c54596e0d127d)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/libtool/libtool-cross_2.4.2.bb

@@ -39,3 +39,5 @@ libtoolcross_sysroot_preprocess () {
 }
 
 SSTATE_SCAN_FILES += "libtoolize *-libtool"
+
+export CONFIG_SHELL="/bin/bash"

meta/recipes-devtools/libtool/libtool-native_2.4.2.bb

@@ -22,3 +22,4 @@ do_install () {
 	install -m 0755 ${HOST_SYS}-libtool ${D}${bindir}/${HOST_SYS}-libtool
 }
 
+export CONFIG_SHELL="/bin/bash"