Manually merge doc fixes from 1.3
diff --git a/include/mbedtls/rsa.h b/include/mbedtls/rsa.h
index 89d61b5..9ff667e 100644
--- a/include/mbedtls/rsa.h
+++ b/include/mbedtls/rsa.h
@@ -43,7 +43,7 @@
#define MBEDTLS_ERR_RSA_BAD_INPUT_DATA -0x4080 /**< Bad input parameters to function. */
#define MBEDTLS_ERR_RSA_INVALID_PADDING -0x4100 /**< Input data contains invalid padding and is rejected. */
#define MBEDTLS_ERR_RSA_KEY_GEN_FAILED -0x4180 /**< Something failed during generation of a key. */
-#define MBEDTLS_ERR_RSA_KEY_CHECK_FAILED -0x4200 /**< Key failed to pass the libraries validity check. */
+#define MBEDTLS_ERR_RSA_KEY_CHECK_FAILED -0x4200 /**< Key failed to pass the library's validity check. */
#define MBEDTLS_ERR_RSA_PUBLIC_FAILED -0x4280 /**< The public key operation failed. */
#define MBEDTLS_ERR_RSA_PRIVATE_FAILED -0x4300 /**< The private key operation failed. */
#define MBEDTLS_ERR_RSA_VERIFY_FAILED -0x4380 /**< The PKCS#1 verification failed. */