tests/qtest: libqos: Rename malloc.h to libqos-malloc.h

tests/qtest: libqos: Rename malloc.h to libqos-malloc.h

The qtest/libqos directory is included via the "-I" option to search
for header files when building qtest. Unfortunately the malloc.h has
a name conflict with the standard libc header, leading to a build
failure on the Windows host, due to the MinGW libc stdlib.h header
file includes malloc.h and it now gets wrongly pointed to the one
in the qtest/libqos directory.

Rename "qtest/libqos/malloc.h" to "qtest/libqos/libqos-malloc.h" to
avoid the namespace pollution.

Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20220824094029.1634519-26-bmeng.cn@gmail.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>