Drop redundant resume_all_vcpus() from main()

VCPUs are either resumed directly via vm_start(), after the incoming
migration is done, or when a continue command is issued. We don't need
the explicit resume before entering main_loop().
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

vl.c

@@ -4415,7 +4415,6 @@ int main(int argc, char **argv, char **envp)
 
     os_setup_post();
 
-    resume_all_vcpus();
     main_loop();
     bdrv_close_all();
     pause_all_vcpus();