OpenFirmware: Assure machine type is initialized

On QEMU's emulation of a PowerPC Old World Mac (g3beige), determine_machine()
returns without setting the machine type to unknown, since the root device
does not provide a device_type property.

Move the variable assignment up a few lines to remedy this.

Closes ticket #6123.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37280 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/boot/platform/openfirmware/start.cpp

@@ -55,6 +55,8 @@ clear_bss(void)
 static void 
 determine_machine(void)
 {
+	gMachine = MACHINE_UNKNOWN;
+
 	int root = of_finddevice("/");
 	char buffer[64];
 	int length;
@@ -64,8 +66,6 @@ determine_machine(void)
 
 	// ToDo: add more, and be as generic as possible
 
-	gMachine = MACHINE_UNKNOWN;
-
 	if (!strcasecmp("chrp", buffer))
 		gMachine = MACHINE_CHRP;
 	else if (!strcasecmp("bootrom", buffer))