RDMA/uverbs: Make the code in ib_uverbs_cmd_verbs() less confusing

This patch reduces the number of #ifdefs and also avoids that
smatch reports the following:

drivers/infiniband/core/uverbs_ioctl.c:276: ib_uverbs_cmd_verbs() warn: if statement not indented
drivers/infiniband/core/uverbs_ioctl.c:280: ib_uverbs_cmd_verbs() warn: possible memory leak of 'ctx'
drivers/infiniband/core/uverbs_ioctl.c:315: ib_uverbs_cmd_verbs() warn: if statement not indented

References: commit fac9658c ("IB/core: Add new ioctl interface")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Matan Barak <matanb@mellanox.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/uverbs_ioctl.c

@@ -241,9 +241,7 @@ static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
 	struct uverbs_attr *curr_attr;
 	unsigned long *curr_bitmap;
 	size_t ctx_size;
-#ifdef UVERBS_OPTIMIZE_USING_STACK_SZ
 	uintptr_t data[UVERBS_OPTIMIZE_USING_STACK_SZ / sizeof(uintptr_t)];
-#endif
 
 	if (hdr->reserved)
 		return -EINVAL;
@@ -269,12 +267,9 @@ static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
 			(method_spec->num_child_attrs / BITS_PER_LONG +
 			 method_spec->num_buckets);
 
-#ifdef UVERBS_OPTIMIZE_USING_STACK_SZ
 	if (ctx_size <= UVERBS_OPTIMIZE_USING_STACK_SZ)
 		ctx = (void *)data;
-
 	if (!ctx)
-#endif
 		ctx = kmalloc(ctx_size, GFP_KERNEL);
 	if (!ctx)
 		return -ENOMEM;
@@ -311,9 +306,7 @@ static long ib_uverbs_cmd_verbs(struct ib_device *ib_dev,
 	err = uverbs_handle_method(buf, ctx->uattrs, hdr->num_attrs, ib_dev,
 				   file, method_spec, ctx->uverbs_attr_bundle);
 out:
-#ifdef UVERBS_OPTIMIZE_USING_STACK_SZ
-	if (ctx_size > UVERBS_OPTIMIZE_USING_STACK_SZ)
-#endif
+	if (ctx != (void *)data)
 		kfree(ctx);
 	return err;
 }