warning fix: remove senseless assignment before bailing out of fn w/error

Change-Id: I822f3adce0eccb880007673d60c7eccf7d36b398
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
Reviewed-on: http://openocd.zylin.com/144
Tested-by: jenkins
Reviewed-by: Peter Stuge <peter@stuge.se>

src/target/mips32_pracc.c

@@ -183,7 +183,6 @@ static int mips32_pracc_exec_read(struct mips32_pracc_context *ctx, uint32_t add
 		/* TODO: send JMP 0xFF200000 instruction. Hopefully processor jump back
 		 * to start of debug vector */
 
-		data = 0;
 		LOG_ERROR("Error reading unexpected address 0x%8.8" PRIx32 "", address);
 		return ERROR_JTAG_DEVICE_ERROR;
 	}