configure uses break outside loop
Description of problem:
When running `configure` in version 7.2.0, the following message is printed multiple times:

```
qemu/configure: line 1885: break: only meaningful in a `for', `while', or `until' loop
```
Steps to reproduce:
Running `configure` should be enough. My complete configure command is:

```
/bin/bash ./configure \
    --prefix=$PREFIX/qemu --sysconfdir=/etc$PREFIX/qemu \
    --includedir=$PREFIX/qemu/include --bindir=$PREFIX/qemu/bin \
    --sbindir=$PREFIX/qemu/sbin --libdir=$PREFIX/qemu/lib/amd64 \
    --libexecdir=$PREFIX/qemu/libexec/amd64 \
    --localstatedir=/var$PREFIX/qemu
```
Additional information:
The `configure` script has `break;` in a conditional, where `:` would suffice (or the conditional could just be negated)