chore: fix some typos in comments (#491)

Signed-off-by: luchenhan <[email protected]>

Author: luchenhan

vector/src/Data/Vector/Generic/Base.hs

@@ -145,7 +145,7 @@ class MVector (Mutable v) a => Vector v a where
   --
   -- > elemseq v x y = (singleton x `asTypeOf` v) `seq` y
   --
-  -- Default defintion: @a@ is not evaluated at all.
+  -- Default definition: @a@ is not evaluated at all.
   elemseq :: v a -> a -> b -> b
 
   {-# INLINE elemseq #-}

vector/src/Data/Vector/Storable/Mutable.hs

@@ -248,7 +248,7 @@ storableSetAsPrim n fp x _y = unsafeWithForeignPtr fp $ \ ptr  -> do
 
 {-
 AFTER primitive 0.7 is pretty old, move to using setPtr. which is really
-a confusing misnomer for whats often called memset (intialize)
+a confusing misnomer for what's often called memset (initialize)
 -}
 -- Fill a memory block with the given value. The length is in
 -- elements of type @a@ rather than in bytes.