user: Restore debug usage message for '-d ?' in user mode emulation

The code which prints the debug usage message on '-d ?' for *-user
has to come before the check for "not enough arguments", so that
"qemu-foo -d ?" prints the list of possible debug log items rather than
the generic usage message. (This was inadvertently broken in commit
c235d738.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

bsd-user/main.c

@@ -856,9 +856,6 @@ int main(int argc, char **argv)
             usage();
         }
     }
-    if (optind >= argc)
-        usage();
-    filename = argv[optind];
 
     /* init debug */
     cpu_set_log_filename(log_file);
@@ -877,6 +874,11 @@ int main(int argc, char **argv)
         cpu_set_log(mask);
     }
 
+    if (optind >= argc) {
+        usage();
+    }
+    filename = argv[optind];
+
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));
 

darwin-user/main.c

@@ -809,9 +809,6 @@ int main(int argc, char **argv)
             usage();
         }
     }
-    if (optind >= argc)
-        usage();
-    filename = argv[optind];
 
     /* init debug */
     cpu_set_log_filename(log_file);
@@ -830,6 +827,11 @@ int main(int argc, char **argv)
         cpu_set_log(mask);
     }
 
+    if (optind >= argc) {
+        usage();
+    }
+    filename = argv[optind];
+
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));
 

linux-user/main.c

@@ -3048,11 +3048,6 @@ int main(int argc, char **argv, char **envp)
             usage();
         }
     }
-    if (optind >= argc)
-        usage();
-    filename = argv[optind];
-    exec_path = argv[optind];
-
     /* init debug */
     cpu_set_log_filename(log_file);
     if (log_mask) {
@@ -3070,6 +3065,12 @@ int main(int argc, char **argv, char **envp)
         cpu_set_log(mask);
     }
 
+    if (optind >= argc) {
+        usage();
+    }
+    filename = argv[optind];
+    exec_path = argv[optind];
+
     /* Zero out regs */
     memset(regs, 0, sizeof(struct target_pt_regs));