tls: keep buffer declaration in a single line

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index 9078c24..c791f81 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -2597,8 +2597,7 @@
     psa_ecc_family_t ecc_family;
     size_t key_len;
     mbedtls_ecp_group_id grp_id;
-    unsigned char buf[
-        PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)];
+    unsigned char buf[PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)];
     mbedtls_ecp_keypair *key;
 #endif /* !MBEDTLS_PK_USE_PSA_EC_DATA */