meson: rename libbasic to libbasic_static

Our variables for internal libraries are named 'libfoo' for the shared lib
variant, and 'libfoo_static' for the static lib variant. The only exception was
libbasic, because we didn't have a shared variant for it. But let's rename it
for consitency. This makes the build config easier to understand.

src/shared/meson.build

@@ -357,7 +357,7 @@ libshared = shared_library(
                      '-Wl,--version-script=' + libshared_sym_path],
         link_depends : libshared_sym_path,
         link_whole : [libshared_static,
-                      libbasic,
+                      libbasic_static,
                       libsystemd_static],
         dependencies : [libshared_deps,
                         userspace],