Our current int_sqrt() is not rough nor any approximation; it
calculates the exact value of: floor(sqrt()). Document this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 lib/int_sqrt.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/lib/int_sqrt.c
+++ b/lib/int_sqrt.c
@@ -10,10 +10,10 @@
 #include <linux/bitops.h>
 
 /**
- * int_sqrt - rough approximation to sqrt
+ * int_sqrt - computes the integer square root
  * @x: integer of which to calculate the sqrt
  *
- * A very rough approximation to the sqrt() function.
+ * Computes: floor(sqrt(x))
  */
 unsigned long int_sqrt(unsigned long x)
 {