openssl: probe the cross compiler regardless of the host CC

libopenssl3 differs between builds depending on the environment of the
build host, e.g. in the images of the Turris Omnia:

  -compiler: arm-openwrt-linux-muslgnueabi-gcc -fPIC -pthread -Os ...
  +compiler: arm-openwrt-linux-muslgnueabi-gcc -fPIC -pthread -Wa,--noexecstack -Os ...
  -  GNU_STACK ... RWE 0x10
  +  GNU_STACK ... RW  0x10

Configure probes whether the assembler supports --noexecstack by running
$CROSS_COMPILE$CC, with CC taken from the environment. A host which sets
CC to select its compiler, e.g. CC=gcc-13, makes it run
arm-openwrt-linux-muslgnueabi-gcc-13, which does not exist, so the flag
is silently dropped and libcrypto ends up with an executable stack.

Pass CC=gcc to Configure, so that it always probes the cross compiler.
With CC=gcc-13 in the environment, the configuration now gets
-Wa,--noexecstack like a build without CC set.

Link: https://github.com/openwrt/openwrt/pull/25719
Signed-off-by: Paul Spooren <mail@aparcar.org>

package/libs/openssl/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=openssl
 PKG_VERSION:=3.5.9
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 PKG_BUILD_FLAGS:=no-mips16 gc-sections no-lto
 
 PKG_BUILD_PARALLEL:=1
@@ -366,6 +366,7 @@ TARGET_LDFLAGS += -Wl,--as-needed
 
 define Build/Configure
 	(cd $(PKG_BUILD_DIR); \
+		CC="gcc" \
 		CFLAGS="$(TARGET_CFLAGS)" \
 		CPPFLAGS="$(TARGET_CPPFLAGS)" \
 		LDFLAGS="$(TARGET_LDFLAGS)" \