bash: disable bash malloc by default

Bash's malloc relies on sbrk which is implemented as a fail-only stub in
musl. Presently, it is disabled when configured for static
libs. Instead, default to using libc malloc.

Fixes:

  # bash
  bash: xmalloc: locale.c:81: cannot allocate 18 bytes (0 bytes allocated)

Signed-off-by: Daniel Sabogal <dsabogalcc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/bash/bash.mk

@@ -9,7 +9,7 @@ BASH_SITE = $(BR2_GNU_MIRROR)/bash
 # Build after since bash is better than busybox shells
 BASH_DEPENDENCIES = ncurses readline host-bison \
 	$(if $(BR2_PACKAGE_BUSYBOX),busybox)
-BASH_CONF_OPTS = --with-installed-readline
+BASH_CONF_OPTS = --with-installed-readline --without-bash-malloc
 BASH_LICENSE = GPL-3.0+
 BASH_LICENSE_FILES = COPYING
 
@@ -24,7 +24,7 @@ BASH_CONF_ENV += \
 
 # The static build needs some trickery
 ifeq ($(BR2_STATIC_LIBS),y)
-BASH_CONF_OPTS += --enable-static-link --without-bash-malloc
+BASH_CONF_OPTS += --enable-static-link
 # bash wants to redefine the getenv() function. To check whether this is
 # possible, AC_TRY_RUN is used which is not possible in
 # cross-compilation.