btrfs: Fix typos in comments and strings

The typos accumulate over time so once in a while time they get fixed in
a large patch.

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d5381f3..5480576 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1203,7 +1203,7 @@ int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
 /*
  * Shannon Entropy calculation
  *
- * Pure byte distribution analysis fails to determine compressiability of data.
+ * Pure byte distribution analysis fails to determine compressibility of data.
  * Try calculating entropy to estimate the average minimum number of bits
  * needed to encode the sampled data.
  *
@@ -1267,7 +1267,7 @@ static u8 get4bits(u64 num, int shift) {
 
 /*
  * Use 4 bits as radix base
- * Use 16 u32 counters for calculating new possition in buf array
+ * Use 16 u32 counters for calculating new position in buf array
  *
  * @array     - array that will be sorted
  * @array_buf - buffer array to store sorting results