clk: clk_round_rate() should return 0, not negative numbers, upon error

[Paul Walmsley]

Update the documentation for clk_round_rate() to state that it should
return 0 rather than a negative error code when it encounters an
error.  This describes how the common clock framework currently works;
howeever, some clock code does not yet align to this.

This change is to prepare for returning unsigned values from
clk_round_rate().

Signed-off-by: Paul Walmsley <pwalmsley at nvidia.com>
Cc: Mike Turquette <mturquette at linaro.org>
Cc: Russell King <linux at arm.linux.org.uk>
---
Applies on v3.13-rc1.

  include/linux/clk.h |    2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/clk.h b/include/linux/clk.h
index 9a6d04524b1a..ffbbb7b2de43 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -228,7 +228,7 @@ void devm_clk_put(struct device *dev, struct clk *clk);
   * @clk: clock source
   * @rate: desired clock rate in Hz
   *
- * Returns rounded clock rate in Hz, or negative errno.
+ * Returns rounded clock rate in Hz, or 0 upon error.
   */
  long clk_round_rate(struct clk *clk, unsigned long rate);