[PATCH] configure: Remove unused variable default_cflags

configure has a variable default_cflags, which was originally added
in commit bafe78ad3bc4c ("contrib/plugins: use an independent
makefile") as part of it setting up the build environment for
contrib/plugins, which at the time used make.  However, we now build
the plugins with meson, and in commit 55c84a72aba4 ("contrib/plugins:
remove Makefile for contrib/plugins") we dropped the logic from
configure that does that makefile setup, leaving default_cflags
as an unused variable.

shellcheck helpfully reports this:
      default_cflags='-O0 -g'
      ^------------^ SC2034 (warning): default_cflags appears unused. Verify use (or export if used externally).

Remove the unused variable.

Signed-off-by: Peter Maydell <[email protected]>
---
 configure | 2 --
 1 file changed, 2 deletions(-)

diff --git a/configure b/configure
index cd1dadd8bb..42c45fe47a 100755
--- a/configure
+++ b/configure
@@ -248,7 +248,6 @@ for opt do
   esac
 done
 
-default_cflags='-O2 -g'
 git_submodules_action="update"
 docs="auto"
 EXESUF=""
@@ -707,7 +706,6 @@ for opt do
       meson_option_parse --enable-debug-graph-lock ""
       meson_option_parse --enable-debug-mutex ""
       meson_option_add -Doptimization=0
-      default_cflags='-O0 -g'
   ;;
   --disable-tcg) tcg="disabled"
   ;;
-- 
2.43.0