libunwind: disable installation of tests dir

fix the issue that:
| Error: Transaction test error:
|   file /usr/libexec/libunwind/check-namespace.sh conflicts between attempted installs of libunwind-1.8.1-r0.core2_64 and lib32-libunwind-1.8.1-r0.core2_32
|   file /usr/libexec/libunwind/test-runner conflicts between attempted installs of libunwind-1.8.1-r0.core2_64 and lib32-libunwind-1.8.1-r0.core2_32

By default, test suite from srcdir/tests/* will be installed to /usr/libexec/libunwind, here pass --disable-tests to not install test suite.
Test suite can be added to libunwind-ptest in the future if needed

(From OE-Core rev: 9d9c36cd5fc59e88bcd8a08ba70ced996c7d74be)

Signed-off-by: Liu Yiding <liuyd.fnst@fujitsu.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/libunwind/libunwind_1.8.1.bb

@@ -28,7 +28,7 @@ PACKAGECONFIG[lzma] = "--enable-minidebuginfo,--disable-minidebuginfo,xz"
 PACKAGECONFIG[zlib] = "--enable-zlibdebuginfo,--disable-zlibdebuginfo,zlib"
 PACKAGECONFIG[latexdocs] = "--enable-documentation, --disable-documentation, latex2man-native"
 
-EXTRA_OECONF = "--enable-static"
+EXTRA_OECONF = "--enable-static --disable-tests"
 
 # http://errors.yoctoproject.org/Errors/Details/20487/
 ARM_INSTRUCTION_SET:armv4 = "arm"