Fix crash on kernels with extended keymap space

The len argument of EVIOCGBIT(ev,len) is the size of the receiving
buffer in bytes, not maximim number of bits to retrieve.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
 eventcomm.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/eventcomm.c b/eventcomm.c
index e3257cd..2d0a347 100644
--- a/eventcomm.c
+++ b/eventcomm.c
@@ -89,7 +89,7 @@ event_query_is_touchpad(int fd)
 
     /* Check for ABS_X, ABS_Y, ABS_PRESSURE and BTN_TOOL_FINGER */
 
-    SYSCALL(ret = ioctl(fd, EVIOCGBIT(0, EV_MAX), evbits));
+    SYSCALL(ret = ioctl(fd, EVIOCGBIT(0, sizeof(evbits)), evbits));
     if (ret < 0)
 	return FALSE;
     if (!TEST_BIT(EV_SYN, evbits) ||
@@ -97,7 +97,7 @@ event_query_is_touchpad(int fd)
 	!TEST_BIT(EV_KEY, evbits))
 	return FALSE;
 
-    SYSCALL(ret = ioctl(fd, EVIOCGBIT(EV_ABS, KEY_MAX), evbits));
+    SYSCALL(ret = ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(evbits)), evbits));
     if (ret < 0)
 	return FALSE;
     if (!TEST_BIT(ABS_X, evbits) ||
@@ -105,7 +105,7 @@ event_query_is_touchpad(int fd)
 	!TEST_BIT(ABS_PRESSURE, evbits))
 	return FALSE;
 
-    SYSCALL(ret = ioctl(fd, EVIOCGBIT(EV_KEY, KEY_MAX), evbits));
+    SYSCALL(ret = ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(evbits)), evbits));
     if (ret < 0)
 	return FALSE;
     if (!TEST_BIT(BTN_TOOL_FINGER, evbits))