transport: Move exception handler to the caller

Move exception handling code to the caller side. This is a preparation
for adding a custom error handler that is similar to UploadPack.

Note that `catch (Throwable t)` will not affect the exception spec since
Java will do an analysis of rethrown exceptions. See
https://docs.oracle.com/javase/8/docs/technotes/guides/language/catch-multiple.html.

Change-Id: I973a63d4b079c2cd1402afb3f2956e18b7d5a00c
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>

org.eclipse.jgit/src/org/eclipse/jgit/transport/ReceivePack.java

 			if (hasCommands()) {
 				readPostCommands(pck);
 			}
-		} catch (PackProtocolException e) {
-			discardCommands();
-			fatalError(e.getMessage());
-			throw e;
-		} catch (InputOverLimitIOException e) {
-			String msg = JGitText.get().tooManyCommands;
+		} catch (Throwable t) {
 			discardCommands();
-			fatalError(msg);
-			throw new PackProtocolException(msg);
+			throw t;
 		}
 	}
 
 			getAdvertisedOrDefaultRefs();
 		if (hasError())
 			return;
-		recvCommands();
+
+		try {
+			recvCommands();
+		} catch (PackProtocolException e) {
+			fatalError(e.getMessage());
+			throw e;
+		} catch (InputOverLimitIOException e) {
+			String msg = JGitText.get().tooManyCommands;
+			fatalError(msg);
+			throw new PackProtocolException(msg);
+		}
+
 		if (hasCommands()) {
 			Throwable unpackError = null;
 			if (needPack()) {