doc: driver-model/platform.txt: fix a typo

The sentence is not proper English, so the use of "general" is now replaced with
"in general". "generally" was also considered, but "in general" is probably the
correct in this case.
Signed-off-by: NLaszlo Papp <lpapp@kde.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Documentation/driver-model/platform.txt

@@ -48,7 +48,7 @@ struct platform_driver {
 	struct device_driver driver;
 };
 
-Note that probe() should general verify that the specified device hardware
+Note that probe() should in general verify that the specified device hardware
 actually exists; sometimes platform setup code can't be sure.  The probing
 can use device resources, including clocks, and device platform_data.