test: load drivers using build directory

Since commit 49b536fc30 ("eal: load only shared libs from driver ..."),
we can specify a build directory to the -d option.

Suggested-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

app/test/meson.build

@@ -492,9 +492,7 @@ foreach arg : fast_tests
 
     if (get_option('default_library') == 'shared' and
         arg[0] == 'event_eth_tx_adapter_autotest')
-        foreach drv:dpdk_drivers
-            test_args += ['-d', drv.full_path().split('.a')[0] + '.so']
-        endforeach
+        test_args += ['-d', dpdk_drivers_build_dir]
     endif
     if is_linux
         test_args += ['--file-prefix=@0@'.format(arg[0])]

drivers/meson.build

@@ -52,6 +52,8 @@ if cc.has_argument('-Wno-format-truncation')
     default_cflags += '-Wno-format-truncation'
 endif
 
+dpdk_drivers_build_dir = meson.current_build_dir()
+
 foreach subpath:subdirs
     drivers = []
     std_deps = []