libcollections: btree/map: fix typos

src/libcollections/btree/map.rs

@@ -656,7 +656,7 @@ pub fn append(&mut self, other: &mut Self) {
     }
 
     /// Constructs a double-ended iterator over a sub-range of elements in the map.
-    /// The simplest way is to use the range synax `min..max`, thus `range(min..max)` will
+    /// The simplest way is to use the range syntax `min..max`, thus `range(min..max)` will
     /// yield elements from min (inclusive) to max (exclusive).
     /// The range may also be entered as `(Bound<T>, Bound<T>)`, so for example
     /// `range((Excluded(4), Included(10)))` will yield a left-exclusive, right-inclusive
@@ -748,7 +748,7 @@ pub fn range<T: ?Sized, R>(&self, range: R) -> Range<K, V>
     }
 
     /// Constructs a mutable double-ended iterator over a sub-range of elements in the map.
-    /// The simplest way is to use the range synax `min..max`, thus `range(min..max)` will
+    /// The simplest way is to use the range syntax `min..max`, thus `range(min..max)` will
     /// yield elements from min (inclusive) to max (exclusive).
     /// The range may also be entered as `(Bound<T>, Bound<T>)`, so for example
     /// `range((Excluded(4), Included(10)))` will yield a left-exclusive, right-inclusive