Left out in commit 22a87800e6 ("configure: expand path variables for
meson configure", 2020-08-21), do it now.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index b9e977f13d..8a3acef89d 100755
--- a/configure
+++ b/configure
@@ -473,7 +473,6 @@ LDFLAGS_SHARED="-shared"
 modules="no"
 module_upgrades="no"
 prefix="/usr/local"
-firmwarepath="\${prefix}/share/qemu-firmware"
 qemu_suffix="qemu"
 slirp=""
 oss_lib=""
@@ -1677,6 +1676,7 @@ for opt do
   esac
 done
 
+firmwarepath="${firmwarepath:-$prefix/share/qemu-firmware}"
 libdir="${libdir:-$prefix/lib}"
 libexecdir="${libexecdir:-$prefix/libexec}"
 includedir="${includedir:-$prefix/include}"
-- 
2.26.2