[librsvg/librsvg-2.46] Makefile.am: Don't use non-portable [[ syntax

[Federico Mena Quintero <federico src gnome org>]

commit 63af5b1ff220ef8f0706a00bc380a1f689f7dd9c
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Tue Dec 10 06:42:09 2019 +0800

    Makefile.am: Don't use non-portable [[ syntax
    
    POSIX shell doesn't support [[ syntax, so using it can causes command
    not found errors.

 Makefile.am | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/Makefile.am b/Makefile.am
index b31c8a1a..7ae36e97 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -189,7 +189,7 @@ librsvg_c_api.la: $(librsvg_c_api_la_OBJECTS) $(LIBRSVG_INTERNALS_SRC) $(LIBRSVG
        PKG_CONFIG='$(PKG_CONFIG)'                                              \
        CARGO_TARGET_DIR=$(CARGO_TARGET_DIR)                                    \
        $(CARGO) --locked build $(CARGO_VERBOSE) $(CARGO_TARGET_ARGS) $(CARGO_RELEASE_ARGS) \
-       && if [[ $$($(NM) -g $(RUST_LIB) | grep "T __*clzsi2" -c) -gt 1 ]] ; then \
+       && if [ "$$($(NM) -g $(RUST_LIB) | grep "T __*clzsi2" -c)" -gt 1 ] ; then \
                $(AR) d $(RUST_LIB) clzsi2.o;                                   \
        fi \
        && cd $(LIBRSVG_BUILD_DIR) && $(LINK) $< && mv $(RUST_LIB) .libs/librsvg_c_api.a