build: Fix multiline string warning

meson expects multiline strings to use different quoting syntax.

Change-Id: I9282587b67e55602f6118710b4568c1993e957f0
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/meson.build b/src/meson.build
index ec981a5..c471f1b 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -46,10 +46,10 @@
 has_dl = false
 if not get_option('dl').disabled()
   dl_dep = meson.get_compiler('cpp').find_library('dl', required: false)
-  has_dl = meson.get_compiler('cpp').links('
+  has_dl = meson.get_compiler('cpp').links('''
     #include <dlfcn.h>
     int main() { dlopen("", 0); }
-  ', dependencies: dl_dep)
+  ''', dependencies: dl_dep)
 endif
 if has_dl
   stdplus_deps += [